Process for preparing poly(arylene sulfide sulfone) with in-situ preparation of alkali metal carboxylate

ABSTRACT

A process for preparing poly(arylene sulfide sulfone) by contacting a dihaloaromatic sulfone, an organic amide, a sulfur-containing compound, water, and an alkali metal carboxylate, wherein the alkali metal carboxylate is prepared in-situ by contacting at least one carboxylic acid with at least one alkali metal hydroxide.

BACKGROUND OF THE INVENTION

This invention relates to the production of poly(arylene sulfidesulfone)s. In one aspect, this invention relates to the production ofpoly(phenylene sulfide sulfone). In another aspect, this inventionrelates to the production of poly(arylene sulfide sulfone)s exhibitinghigh molecular weight. In a further aspect, this invention relates tothe production of poly(phenylene sulfide sulfone) exhibiting highmolecular weight.

Poly(arylene sulfide sulfone)s are engineering thermoplastics ofpotential commercial interest for film, fiber, molding, and compositeapplications because of their high glass transition temperatures andchemical resistance.

General processes for the production of poly(arylene sulfide sulfone)sare known. Poly(arylene sulfide sulfone)s can be prepared by thereaction of a polyhaloaromatic sulfone, such asbis(4-chlorophenyl)sulfone, with an alkali metal sulfide in the presenceof a polar organic compound.

U.S. Pat. No. 4,016,145 discloses the use of alkali metal carboxylateand U.S. Pat. No. 4,127,713 discloses the use of sodium carboxylate toincrease the molecular weight of poly(arylene sulfide sulfone)s.Although these patents represent significant and valuable advances inthe art, there is a need for a process which can provide high molecularweight poly(arylene sulfide sulfone)s without the problems associatedwith handling alkali metal carboxylate. For example, use of aqueousalkali metal carboxylate solutions as a feedstock in the preparation ofpoly(arylene sulfide sulfone)s necessitates storing and handling a largevolume of liquid to enable charging the desired amount of alkali metalcarboxylate. Similarly, use of solid alkali metal carboxylate as afeedstock in the preparation of poly(arylene sulfide sulfone)snecessitates storing and handling a solid to enable charging the desiredamount of alkali metal carboxylate. It has now been discovered thatunexpectedly good results can be obtained using alkali metal carboxylateprepared in-situ by contacting a carboxylic acid with an alkali metalhydroxide in the production of poly(arylene sulfide sulfone)s.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a process for producing highmolecular weight poly(arylene sulfide sulfone) by using an alkali metalcarboxylate prepared in-situ by contacting a carboxylic acid with analkali metal hydroxide. It is a further object of the invention toprovide a process for producing poly(arylene sulfide sulfone) with highrecoverable yield by using an alkali metal carboxylate prepared in-situby contacting a carboxylic acid with an alkali metal hydroxide.

According to the invention, a process for preparing poly(arylene sulfidesulfone)s is provided which comprises contacting at least onedihaloaromatic sulfone, at least one organic amide, at least onesulfur-containing compound, water, and at least one alkali metalcarboxylate, wherein the alkali metal carboxylate is prepared in-situ bycontacting at least one carboxylic acid with at least one alkali metalhydroxide.

DETAILED DESCRIPTION OF THE INVENTION

This invention relates to a process for preparing poly(arylene sulfidesulfone) polymers comprising contacting: (a) at least one dihaloaromaticsulfone, (b) at least one organic amide, (c) at least onesulfur-containing compound, (d) water, and (e) at least one alkali metalcarboxylate, wherein the alkali metal carboxylate is prepared in-situ bycontacting at least one carboxylic acid with at least one alkali metalhydroxide. The high molecular weight poly(arylene sulfide sulfone)s madeaccording to this invention are readily recoverable and well suited foruse in applications such as film, fiber, molding, and composites.

Inherent viscosity is a measure of molecular weight which isparticularly useful in characterizing poly(arylene sulfide sulfone)s. Asused herein, the term "inherent viscosity" (I.V.) refers to dilutesolution viscosity which is the ratio of the natural logarithm of therelative viscosity to the polymer solution concentration in grams perdeciliter. The relative viscosity is the ratio of the flow time of aspecific solution of the polymer to the flow time of the pure solvent.Inherent viscosities for poly(arylene sulfide sulfone)s are measuredgenerally according to the method described in ASTM D1243-79 whereinsamples of dried polymer are dissolved in N-methyl-2-pyrrolidone at 30°C. at a polymer concentration of 0.5 grams per deciliter (g/dL)utilizing a No. 100 Cannon-Fenske Viscometer.

Dihaloaromatic sulfones employed in the process of the invention can berepresented by the formula ##STR1## wherein each X is selected from thegroup consisting of fluorine, chlorine, bromine, and iodine, Z is adivalent radical selected from the group consisting of ##STR2## whereinm is 0 or 1, n is 0 or 1 A is selected from the group consisting ofoxygen, sulfur, sulfonyl, and CR₂, wherein each R is selected from thegroup consisting of hydrogen and alkyl radicals having 1 to about 4carbon atoms, the total number of carbon atoms in all of the R groups inthe molecule being 0 to about 12. Preferably m is 0 and thedihaloaromatic sulfone of the invention is represented by the formula##STR3## wherein each X is selected from the group consisting offluorine, chlorine, bromine, and iodine, and each R is selected from thegroup consisting of hydrogen and alkyl radicals having 1 to about 4carbon atoms, the total number of carbon atoms in all of the R groups inthe molecule being 0 to about 12.

Examples of some dihaloaromatic sulfones that can be employed in theprocess of the invention include bis(4-fluorophenyl)sulfone,bis(4-chlorophenyl)sulfone, bis(4-bromophenyl)sulfone,bis(4-iodophenyl)sulfone, p-chlorophenyl p-bromophenylsulfone,p-iodophenyl 3-methyl-4-fluorophenylsulfone,bis(2-methyl-4-chlorophenyl)sulfone,bis(2,5-diethyl-4-bromophenyl)sulfone,bis(3-isopropyl-4-iodophenyl)sulfone,bis(2,5-dipropyl-4-chlorophenyl)sulfone,bis(2-butyl-4-fluorophenyl)sulfone,bis(2,3,5,6-tetramethyl-4-chlorophenyl)sulfone,2-isobutyl-4-chlorophenyl 3-butyl-4-bromophenylsulfone,1,4-bis(p-chlorophenylsulfonyl)benzene,1-methyl-2,4-bis(p-fluorophenylsulfonyl)benzene,2,6-bis(p-bromophenylsulfonyl)naphthalene,7-ethyl-1,5-bis(p-iodophenylsulfonyl)naphthalene,4,4'-bis(p-chlorophenylsulfonyl)biphenyl,bis[p-(p-bromophenylsulfonyl)phenyl]ether,bis[p-(p-chlorophenylsulfonyl)phenyl]-sulfide,bis[p-(p-chlorophenylsulfonyl)phenyl]sulfone,bis[p-(p-bromophenylsulfonyl)phenyl]methane,5,5-bis[3-ethyl-4-(p-chlorophenylsulfonyl)phenyl]nonane, and the like,and mixtures thereof. The presently preferred dihaloaromatic sulfone isbis(4-chlorophenyl)sulfone because of its effectiveness and commercialavailability.

The amount of dihaloaromatic sulfone employed in the invention dependsupon the amount of sulfur-containing compound employed The amount ofdihaloaromatic sulfone can be expressed in terms of a molar ratio ofdihaloaromatic sulfone to sulfur-containing compound and Will generallybe about 0.7:1 to about 1.3:1. Preferably, this molar ratio is about0.9:1 to about 1.15:1.

The organic amides used in the process of the invention should besubstantially liquid at the reaction temperature and pressure employed.The amides can be cyclic or acyclic and can have 1 to about 10 carbonatoms per molecule. Examples of some suitable amides include formamide,acetamide, N-methylformamide, N,N-dimethylformamide,N,N-dimethylacetamide, N-ethylpropionamide, N,N-dipropylbutyramide,2-pyrrolidone, N-methyl-2-pyrrolidone, ε-caprolactam,N-methyl-ε-caprolactam, N-ethyl-2-pyrrolidone,N-cyclohexyl-2-pyrrolidone, N-dodecyl-3-octyl-2-pyrrolidone,N,N'-ethylenedi-2-pyrrolidone, hexamethylphosphoramide, tetramethylurea,and the like, and mixtures thereof.

The amounts of organic amide employed according to the invention can beexpressed in terms of molar ratio based on the sulfur-containingcompound employed. Broadly, the molar ratio of organic amide tosulfur-containing compound will be about 2:1 to about 24:1, preferablyabout 4:1 to about 16:1. N-methyl-2-pyrrolidone is especially preferredbecause of excellent results and ready availability.

In accordance with the invention, suitable sulfur-containing compoundswhich can be employed in the production of the poly(arylene sulfidesulfone)s can be selected from the group consisting of alkali metalsulfides, alkali metal bisulfides, and hydrogen sulfide. Suitable alkalimetal sulfides include lithium sulfide, sodium sulfide, potassiumsulfide, rubidium sulfide, and cesium sulfide, and mixtures thereof. Thealkali metal sulfide can be used in anhydrous form, as a hydrate, or asan aqueous mixture. Sodium sulfide is preferred because of readyavailability and good results obtained therewith. Suitable alkali metalbisulfides include lithium bisulfide, sodium bisulfide, potassiumbisulfide, rubidium bisulfide, cesium bisulfide, and mixtures thereof.Sodium bisulfide is preferred because of ready availability and goodresults obtained therewith. The alkali metal bisulfide can convenientlybe utilized in the process of the invention as an aqueous solution. Forexample, an aqueous solution of sodium bisulfide having about 60 wt. %sodium bisulfide is convenient to use.

The amount of water employed according to the invention can be expressedin terms of molar ratio based on the organic amide employed. Broadly,the molar ratio of organic amide to water will be from about 0.4:1 toabout 1.6:1, preferably about 0.45:1 to about 1.3:1, and most preferablyabout 0.5:1 to about 1:1.

Alkali metal carboxylates that can be employed in the process of theinvention can be represented by the formula R'CO₂ M where R' is ahydrocarbyl radical selected from alkyl, cycloalkyl, aryl andcombinations thereof such as alkaryl, aralkyl, and the like, the numberof carbon atoms in said R' being within the range of 1 to about 20, andM is an alkali metal selected from lithium, sodium, potassium, rubidium,and cesium.

Examples of some alkali metal carboxylates that can be employed in theprocess of the invention include lithium acetate, sodium acetate,potassium acetate, lithium propionate, sodium propionate, lithium2-methyl-propionate, rubidium butyrate, lithium valerate, sodiumvalerate, cesium hexanoate, lithium heptanoate, lithium2-methyloctanoate, potassium dodecanoate, rubidium4-ethyltetradecanoate, sodium octadecanoate, sodium heneicosanoate,lithium cyclohexane carboxylate, cesium cyclododecane carboxylate,sodium 3-methylcyclopentane carboxylate, potassium cyclohexylacetate,potassium benzoate, lithium benzoate, sodium benzoate, potassiumm-toluate, lithium phenylacetate, sodium 4-phenylcyclohexanecarboxylate, potassium p-tolylacetate, lithium 4-ethylcyclohexylacetateand the like and mixtures thereof. The presently preferred alkali metalcarboxylate is sodium acetate because of its effectiveness andcommercial availability.

According to the invention, the alkali metal carboxylate employed isprepared in-situ by contacting at least one carboxylic acid with atleast one alkali metal hydroxide. Carboxylic acids that can be employedin the process of the invention can be represented by the formula R'COOHwherein R' is a hydrocarbyl radical selected from alkyl, cycloalkyl,aryl and combinations thereof such as alkaryl, aralkyl, and the like,the number of carbon atoms in said R' being within the range of 1 toabout 20. Alkali metal hydroxides that can be employed according to theinvention include lithium hydroxide, sodium hydroxide, potassiumhydroxide, rubidium hydroxide, cesium hydroxide, and mixtures thereof.Sodium hydroxide is preferred because of ready availability and goodresults obtained using this compound. The alkali metal hydroxide canconveniently be utilized in the process of the invention as an aqueoussolution. For example, an aqueous solution of sodium hydroxide havingabout 50 wt. % sodium hydroxide is convenient to use.

In a preferred embodiment, the carboxylic acid is contacted with thealkali metal hydroxide prior to subjecting to polymerization mixture topolymerization conditions of temperature and time sufficient to form thepoly(arylene sulfide sulfone).

Examples of some carboxylic acids that can be employed in the process ofthe invention include acetic acid, propionic acid, butyric acid, valericacid, hexanoic acid, heptanoic acid, methyl octanoic acid, dodecanoicacid, 4-ethyltetradecanoic acid, cyclododecanoic acid,3-methylcyclopentanoic acid, cyclohexanoic acid, heneicosanoic acid,octanoic acid, benzoic acid, m-toluic acid, phenyl acetic acid,cyclohexane carboxylic acid, 4-phenylcyclohexane carboxylic acid,p-tolylaceiic acid, 4-ethylcyclohexane carboxylic acid, and the like andmixtures thereof. The presently preferred carboxylic acid is acetic acidbecause of its effectiveness and commercial availability.

The amounts of alkali metal hydroxide and carboxylic acid used toprepare the alkali metal carboxylate can conveniently be expressed interms of molar ratio of alkali metal hydroxide used to prepare saidalkali metal carboxylate to said carboxylic acid and the molar ratio ofin-situ prepared alkali metal carboxylate employed to saidsulfur-containing compound employed. Broadly, the molar ratio of saidalkali metal hydroxide used to prepare said alkali metal carboxylate tosaid carboxylic acid is about 0.95:1 to about 1.05:1, preferably about0.98:1 to about 1.02:1, and most preferably in essentiallystoichiometric amounts. Broadly, the molar ratio of alkali metalcarboxylate to sulfur-containing compound will be from about 0.002:1 toabout 4:1, preferably about 0.005:1 to about 2:1, and most preferablyabout 0.01:1 to about 1.2:1.

In a preferred embodiment, in addition to the alkali metal hydroxideused to prepare the alkali metal carboxylate, a base selected from thegroup consisting of alkali metal hydroxide, alkali metal carbonate, andmixtures of at least one alkali metal hydroxide with at least one alkalimetal carbonate is employed when the sulfur-containing compound is analkali metal bisulfide or hydrogen sulfide.

Alkali metal hydroxides that can be employed according to the inventioninclude lithium hydroxide, sodium hydroxide, potassium hydroxide,rubidium hydroxide, cesium hydroxide, and mixtures thereof. Sodiumhydroxide is preferred because of ready availability and good resultsobtained using this compound. The alkali metal hydroxide canconveniently be utilized in the process of the invention as an aqueoussolution. For example, an aqueous solution of sodium hydroxide havingabout 50 wt. % sodium hydroxide is convenient to use.

Alkali metal carbonates that can be employed according to the inventioninclude lithium carbonate, sodium carbonate, potassium carbonate,rubidium carbonate, cesium carbonate, and mixtures thereof. Sodiumcarbonate is preferred because of ready availability and generally goodresults obtained therewith.

If a mixture of at least one alkali metal hydroxide and at least onealkali metal carbonate is employed, said mixture should contain at leastabout 5 mole percent alkali metal carbonate. Preferably, said mixturewill have about 20 to about 90 mole percent alkali metal carbonate andmore preferably about 40 to about 80 mole percent alkali metalcarbonate.

When additional base is employed according to the preferred embodimentof the invention, the molar ratio of the base to the sulfur-containingcompound is about 0.5:1 to about 4:1, preferably about 0.5:1 to about2.05:1.

The charge sequence of the various compounds employed in the process ofthe invention can be varied as desired. One convenient method is tosimply charge all the compounds in any desired sequence to a suitablereaction vessel equipped with agitation means at about room temperatureand then to heat the mixture with stirring to the desired reactiontemperature and to hold the mixture for the desired length of time atsaid temperature. It is also possible to preheat a mixture of onlycertain of the compounds in a separate vessel then to charge thismixture to the preheated mixture of the remainder of the compounds inthe reaction vessel. For example, an organic amide can be prereactedwith an alkali metal hydroxide in the presence of water, and thismixture subsequently contacted with the sulfur-containing compound toform a complex comprising these components. The complex is then utilizedto contact a mixture containing an alkali metal carboxylate preparedin-situ from a carboxylic acid and an alkali metal hydroxide in thepresence of water, and at least one dihaloaromatic sulfone undersuitable polymerization conditions to produce the poly(arylene sulfidesulfone). Although the reaction temperature at which the polymerizationis conducted can vary over a considerable range, generally it will bewithin the range of about 140° C. to about 240° C., preferably about185° C. to about 225° C. The reaction time can vary widely, depending inpart on the reaction temperature employed, but generally will be withinthe range of about 10 minutes to about 72 hours, preferably about 1 hourto about 4 hours. The pressure should be sufficient to maintain thedihaloaromatic sulfone and other organic compounds present substantiallyin the liquid phase.

The poly(arylene sulfide sulfone)s as produced by the process of theinvention are in particle form and can be separated from the reactionmixture by conventional procedures, e.g. by filtration of the reactionmixture to recover the polymer followed by washing at least once withwater. A presently preferred recovery method involves diluting the hotreaction mixture with a mixture of water and organic amide and coolingthe diluted liquid while stirring. The separated polymer particles canthen be washed with water preferably with at least a portion of thewashing being conducted at an elevated temperature within the range ofabout 130° C. to about 250° C. and then dried to provide a polymer whichis low in ash forming substances and is relatively light in color aswell as exhibiting good melt flow stability under conditions of meltprocessing operations such as injection molding. In addition, it ispresently preferred to employ a zinc carboxylate salt in the treatmentof the recovered poly(arylene sulfide sulfone) in at least one of theabove-described washing steps.

The poly(arylene sulfide sulfone)s produced by the process of theinvention can be blended with fillers, fibers, pigments, extenders,other particles and the like. The poly(arylene sulfide sulfone)s can becured to provide cured products having high thermal stability and goodchemical resistance, wherein curing is defined as a distinct processstep after polymer drying comprising a thermal treatment on the polymerin the presence of an oxygen-containing atmosphere. The preferredoxygen-containing atmosphere is air. The poly(arylene sulfide sulfone)sof the invention are useful in the production of film, fibers, moldedobjects, and composites.

EXAMPLES EXAMPLE I

A series of polymerization runs were performed in a one gallon, faststirring reactor for the preparation of poly(phenylene sulfide sulfone)(PPSS). The polymerization recipe for these runs is presented below.

    ______________________________________                                                           Compound, g-mole                                           ______________________________________                                        Bis(4-chlorophenyl)sulfone (BCPS)                                                                  1.0                                                      Sodium bisulfide (NaSH).sup.(a)                                                                    1.0                                                      Sodium hydroxide (NaOH).sup.(b)                                                                    1.0-2.0                                                  N-methyl-2-pyrrolidone (NMP)                                                                       8.0                                                      Water (H.sub.2 O).sup.(c)                                                                          5.1-6.2                                                  Sodium acetate (NaOAc)                                                                             0.0-1.0                                                  Acetic acid (HOAc)   0.0-1.0                                                  ______________________________________                                         .sup.(a) Charged as a solid NaSH--H.sub.2 O solution containing 58.5-59.9     weight percent NaSH.                                                          .sup.(b) Includes the NaOH required for preparing the sodium acetate          insitu and the NaOH for use with the NaSH.                                    .sup.(c) Includes water added, water present in NaSH and water produced b     the reaction of NaOH and HOAc.                                           

In each run the reactor was charged with BCPS, NaSH, NaOH, NMP, H₂ O andoptionally NaOAc. The reactor was sealed, agitation started anddegassing accomplished by three pressurize-release cycles usingnitrogen. For the runs in which NaOAc was prepared in-situ, HOAc wasthen charged using a nitrogen degassed and nitrogen pressurized 150 mLcylinder. The temperature of the reaction mixture was raised to 200° C.and held for 3 hours. At this time, heating was terminated and a mixtureof 500 mL NMP and 175-250 mL H₂ O was charged to the reactor. Thetemperature of the reaction temperature dropped to 175°-181° C. uponaddition of the NMP-H₂ O mixture. The reaction mixture was then cooledslowly.

The PPSS reaction mixture was separated using a No. 100 U.S.A. Sieve(150 microns). The material retained on the screen was washed withambient distilled water and filtered three to four times. The finalfilter cake was then rinsed with acetone. The polymer was dried in avacuum oven and weighed. Recoverable yield was calculated by dividingthe weight of material retained on the screen by the weight of polymerproduced assuming 100% conversion. A 60-75 gram sample of the washedpolymer was charged to the reactor with 550 mL distilled H₂ O. Thereactor was sealed, agitation started and degassing accomplished bythree pressurize-release cycles using nitrogen The temperature of theslurry was raised to 180° C. and held for 30 minutes, then cooled. Thereactor was opened, the liquid drawn off and the remaining polymerwashed twice in the reactor with ambient distilled H₂ O and the liquiddrawn off. To the reactor was added 550 mL distilled H₂ O and 10 gramsof zinc acetate. The reactor was sealed, agitation started and degassingaccomplished by three pressurize-release cycles using nitrogen. Thetemperature of the slurry was raised to 180° C. and held for 30 minutes,then cooled. The reactor was opened, the slurry filtered and the polymerrinsed with acetone. The polymer was then dried in a vacuum oven, and asample tested for inherent viscosity.

The results obtained are presented in Table I.

                  TABLE I                                                         ______________________________________                                                                                   Recov-                                                                        erable                             Run  NMP/H.sub.2 O,.sup.(a)                                                                   NaOAc    HOAc  NaOH  I.V..sup.(b)                                                                        Yield,                             No.  Mole Ratio g-mole   g-mole                                                                              g-mole                                                                              (dL/g)                                                                              %                                  ______________________________________                                        1    1.54       --       1.0   2.0   0.50  92.3                               2    1.29       --       1.0   1.99  0.44  89.                                3    1.54       --       1.0   1.99  0.46  N.D..sup.(c)                       4    1.54       --       1.0   1.99  0.33  N.D..sup.(c)                       5.sup.(d)                                                                          1.57       1.0      --    1.0   0.39  81.                                6.sup.(d)                                                                          1.57       1.0      --    1.0   0.36  81.2                               ______________________________________                                         .sup.(a) Includes H.sub.2 O added, H.sub.2 O present in NaSH and H.sub.2      produced by the reaction of NaOH and HOAc.                                    .sup.(b) Inherent viscosity.                                                  .sup.(c) Not determined.                                                      .sup.(d) Control run.                                                    

The results in Table I indicate that PPSS produced with in-situgenerated sodium acetate (Runs 1-3) has higher molecular weight, asmeasured by inherent viscosity, and higher recoverable yield than PPSSproduced with added sodium acetate (Runs 5 and 6).

It is unclear why the molecular weight of Run 4 was significantly lowerthan that of the other runs made according to the invention. However, itis noted that the fine oligomeric material produced in this run had ayellow color whereas the normal color of such material is grey,indicating that Run 4 is apparently an anomaly.

Therefore, the results indicate that unexpectedly good results can beobtained using in-situ generated alkali metal carboxylate in thepolymerization of poly(arylene sulfide sulfone). Use of in-situgenerated alkali metal carboxylate produces polymer having highermolecular weight and higher recoverable yield than polymers producedwhen the alkali metal carboxylate is added to the polymerization.

That which is claimed is:
 1. A process for the production ofpoly(arylene sulfide) sulfone comprising contacting:(a) at least onedihaloaromatic sulfone, (b) at least one organic amide, (c) at least onesulfur-containing compound, (d) water, and (e) at least one alkali metalcarboxylate, wherein the said alkali metal carboxylate is preparedin-situ by contacting at least one carboxylic acid with at least onealkali metal hydroxide.
 2. A process according to claim 1 wherein saidcarboxylic acid is represented by the formula R'COOH wherein R' is ahydrocarbyl radical containing 1 to about 20 carbon atoms.
 3. A processaccording to claim 2 wherein said alkali metal carboxylate isrepresented by the formula R'CO₂ M wherein R' is a hydrocarbyl radicalcontaining 1 to about 20 carbon atoms, and M is an alkali metal.
 4. Aprocess according to claim 3 wherein the molar ratio of said alkalimetal hydroxide used to prepare said alkali metal carboxylate to saidcarboxylic acid is about 0.95:1 to about 1.05:1.
 5. A process accordingto claim 4 wherein the molar ratio of said dihaloaromatic sulfone tosaid sulfur-containing compound is about 0.7:1 to about 1.3:1.
 6. Aprocess according to claim 5 wherein the molar ratio of said organicamide to said sulfur-containing compound is about 2:1 to about 24:1. 7.A process according to claim 6 wherein the molar ratio of said organicamide to said water is about 0.4:1 to about 1.6:1.
 8. A processaccording to claim 7 wherein said dihaloaromatic sulfone is representedby the formula ##STR4## wherein each X is selected from the groupconsisting of fluorine, chlorine, bromine and iodine, Z is a divalentradical selected from the group consisting of ##STR5## m is 0 or 1, n is0 or 1, A is selected from the group consisting of oxygen, sulfur,sulfonyl, and CR₂, wherein each R is selected from the group consistingof hydrogen and alkyl radicals having 1 to about 4 carbon atoms, thetotal number of carbon atoms in all of the R groups in the moleculebeing 0 to about
 12. 9. A process according to claim 8 wherein saidorganic amide is selected from the group consisting of cyclic andacyclic organic amides having 1 to about 10 carbon atoms per molecule.10. A process according to claim 9 wherein said sulfur-containingcompound is selected from the group consisting of alkali metal sulfides,alkali metal bisulfides and hydrogen sulfide.
 11. A process according toclaim 10 further comprising adding additional base selected from thegroup consisting of alkali metal hydroxide, alkali metal carbonate, andmixtures of at least one alkali metal hydroxide with at least one alkalimetal carbonate.
 12. A process according to claim 11 wherein saidcarboxylic acid is contacted with said alkali metal hydroxide prior tosubjecting the polymerization mixture to polymerization conditions oftemperature and time sufficient to form said poly(arylene sulfide)sulfone.
 13. A process according to claim 12 wherein said carboxylicacid is acetic acid, said alkali metal hydroxide is sodium hydroxide andsaid alkali metal carboxylate is sodium acetate.
 14. A process accordingto claim 13 wherein m is 0 and said aloaromatic sulfone is representedby the formula ##STR6## wherein each X is selected from the groupconsisting of fluorine, chlorine, bromine, and iodine, and each R isselected from the group consisting of hydrogen and alkyl radicals having1 to about 4 carbon atoms, the total number of carbon atoms in all ofthe R groups in the molecule being 0 to about
 12. 15. A processaccording to claim 14 wherein said poly(arylene sulfide sulfone) ispoly(phenylene sulfide sulfone).
 16. A process according to claim 15wherein said molar ratio of said alkali metal carboxylate to saidsulfur-containing compound is about 0.002:1 to about 4:1.
 17. A processfor the production of poly(phenylene sulfide sulfone) comprisingcontacting:(a) bis(4-chlorophenyl)sulfone, (b) N-methyl-2-pyrrolidone,(c) sodium bisulfide, (d) sodium hydroxide, (e) water, and (f) sodiumacetate wherein said sodium acetate is prepared in-situ by contactingacetic acid with sodium hydroxide.
 18. A process for the production ofpoly(arylene sulfide sulfone) comprising the steps of:(a) contacting atleast one dihaloaromatic sulfone, at least one organic amide, at leastone sulfur-containing compound, water, at least one alkali metalhydroxide, and at least one carboxylic acid to form a mixture, (b)heating said mixture under conditions of temperature and time sufficientto form said poly(arylene sulfide sulfone), and (c) recovering saidpoly(arylene sulfide sulfone).